JPH0389082A - Gate valve - Google Patents

Abstract

PURPOSE: To provide an improved seating mechanism for a gate valve having a metal-to-metal sealing mechanism by composing each seat mechanism of an assembly in which a sealing member is energized by a disc spring to seal a seat to a main body seal surface. CONSTITUTION: An assembly 60 to deflect metal C-ring seals 52, 54 to be sealed/ engaged with a main body sealing surface 46 is disposed in a seating pocket 40 around an outer circumference of a seat 42. The assembly 60 is composed of a disc or bevel spring 62 applied to a seat shoulder 51, a circular load ring 64, and a partition holding ring 66 disposed in a circular groove 47 formed in a circumferential wall of a recessed place. By spring force generated by the disc spring 62, the seat 42 is constantly held in a permanent contact condition with the main body sealing surface 46 to energize the metal C-rings 52, 54, thereby metal tightness is generated between the seat 42 and the main body sealing surface 46.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a gate valve. Gate valve is 1
It consists of a body with an inner gate cavity positioned generally perpendicular to a flow hole extending through the body and communicating with all the inlet and exit side holes of the body. A gate is placed within this cavity and the gate is moved by external means 3c. With the gate in the closed position, flow between the holes on the entrance and exit sides is sealed, and with the gate in the open position, flow through the holes is allowed.

(B) Prior Art A gate valve is known which has an inlet/outlet side flow hole passing through the main body together with the gate sealing surface and has a seating mechanism on either side of the gate that engages with the main body surface. This kind of seating is done at the position where the entrance/exit side hole communicates with the gate cavity.
It is generally located within an annular recess, known as a seating pocket, provided within the body around the entry/exit hole.

Many structures are known for such seating structures. A problem with such construction is providing an effective full metal seal between the seat and the body. This does not provide a compatible seal, but protects tight sealing surfaces from wellbore special impurities. For example, it is known to provide a non-metallic seal either on the outer diameter of the seat or on the end face of the seat where the seat abuts the body.

Another construction uses an inner and outer metal sealing ring, such as a metal C-ring seal provided with an inner and outer groove circle Y on the end face of the seat. It is locked in place within the recess by a locking ring. The locking ring is itself held in place by a retaining wire. The locking ring biases the C-IJ seal and the seat/body seal. It is used to load the seal against the body to create a seal.A known problem is that the 2% different design entails a largely uneven loading of the seating mechanism after installation which introduces a reduced sealing function. .

U.S. Pat. No. 2,777.664 discloses various shapes of metal-to-metal seals for use with gate valve buttons and ball valves. Constructions suitable for use with gate valves require welding the seal body to the valve body.

U.S. Pat. No. 6,497,177 shows a seal assembly for a gate valve in which a Belleville spring is used to hold an elastomeric seal in face contact with the gate.

No metal-to-metal seal is provided.

U.S. Pat. No. 3,771,545 discloses a Belleville spring used within a ball valve to maintain an entomer seven-ruling in sealing engagement with a spherical closure member.

U.S. Pat. No. 4,217,923 shows a spring metal cylindrical bellows with pivoting combination with a C-shaped metal seal on the valve seat used in a ball valve.

(c) Problems to be Solved by the Invention An object of the present invention is to provide an improved seating mechanism for a gate valve having a metal-to-metal sealing function.

Another object of the invention is to provide a seated sealing arrangement in which the metal-to-metal seal between the valve seat and the body cavity is maintained as the seal undergoes normal wear.

B) Means for Solving the Problems The gate valve of the present invention includes a main body having a gate cavity and a communication hole extending through and opening into the cavity, and a body having a main body having a gate cavity and a communication hole extending through and opening into the cavity; a recess or seat pocket extending into the recess, a seat mechanism disposed within each recess, a sealing member associated with each seat mechanism for sealing a sealing surface of the body, and a sealing member disposed within the cavity between the seat mechanisms; and a gate positioned stationary and movable to open and close a flow path through the flow hole;
The above problem is solved by means comprising an assembly that biases the sealing member with a disk spring to seal between the sheet and the main body sealing surface.

(E) Embodiment As shown in Figure 3, the gate valve is made up of a main body 12. The body 12 has an outlet 16 and an inlet 14 that communicate with a gate cavity 18.
It has One slab gate valve 20 has a cavity 1
8 and a position for directing fluid between the ports 16 and 14 by suitable actuating means in the vertical direction through the stem 22.

Moves between positions to block and seal the flow. bonnet 24
is fixed to the main body 12. The stem 22 is the bonnet 24
and is sealed thereto by a seal assembly 30.

Entrance/exit 16.14 is an annular recess or seating pocket 40
and the empty space 18 on both sides of the intersection.

These annular recesses accommodate the valve seats 42. As shown in FIG. 2, each seating pocket has a large diameter portion 41 and a small diameter portion 45. As shown in FIG. A portion 41 extends from the gate cavity 18 over a substantial portion in the axial direction of the recess, and one portion 46 terminates in the body sealing surface 46. The wall of the large diameter section 41 has a rectangular section with intermittent cutting annular grooves 47 throughout.

Each seat is annular, with a main part 44 and a body contact surface 4
It has a large diameter portion 49 near 6.

The main portion 44 is located within the recess 41 and also within the cavity 18
It protrudes to a position adjacent to the gate 20 within. circular shoulder 5
1 is bottomed in the common part of the seating part 44,49. The end faces of the seating adjacent to the body sealing surface 46 have inner and outer annular grooves 48 .
5 (J'). Each annular groove has a metal unidirectional C-
Accommodates IJ seals 52°54.

An assembly 60 biased into sealing engagement with the body sealing surface 46 on the seals 52 , 54 ′ is disposed within the seating socket 40 around the outer periphery of the seat 42 .

This assembly consists of a disc or bevil spring 62 abutting the seating shoulder 51, an annular load ring 64, and a split retaining ring 66 disposed in an annular groove 47 molded into the peripheral wall of the recess.
It is made up of. The spring force generated by the disc spring 62 biases the metal C-ring 52.54i sufficiently to maintain the seat 42 in permanent contact with the body sealing surface 46 at all times, thereby causing the seat to connect with the body seating surface. Metal adhesion occurs between the two. This method of sealing prevents the ingress of particular impurities between the seat and the body surface which, if allowed, could be introduced into the holes and eventually overflow and leak. The effective positioning of the C-ring ensures that there is no separation between the seat and the body during valve operation.

Numerical pressure fluctuations bias the seat 42 into the seat pocket even in the event of an inevitable rupture of the C-ring.

Preventing possible crushing into the flow hole of the inner C-ring seal 52 on leakage of the outer C-ring seal 54 is molded into the inner groove 48 on the seat 42. This lip provides additional support to the inner C-ung seat 52 when subjected to counter pressure.

The opposite end sealing surface 70 of the valve seat relies on good surface finish and flatness characteristics to provide a metal-to-metal seal when the gate is moved to its closed position.

A doorway seating member is disposed within each of the seating pockets to configure the seating mechanism. At this stage, gate 2
0. Stem 22. Or neither bonnet 24 is in place. On the other hand, a one-circle leaf spring 62. load ring 64
．． A retaining ring 66 is placed around the outer circumference of the seat 9 and is pressed against the seat shoulder 51 by a hydraulic jacking tool.

- Once a sufficient load has been applied to the load ring and thus the disk spring, the retaining ring 66 is forced downwardly by a suitable tool into a groove formed in the peripheral wall of the recess in the body. The jacked tool load is released with the mechanism in a sufficiently locked condition. The same procedure is performed on the hypothetical opposite side where the gate is installed.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a gate valve according to the present invention. FIG. 2 is an enlarged partial view of the root assembly according to the present invention. 2 6 0 4 1 6 0 4 two bodies :Exit ;gate valve :bonnet Two person diameter part Two body contact surfaces :Aggregation :Load ring 14: Entrance 18: Gate empty space 22: Stem 40: Seating pocket 46: Small diameter part 52.54: C-ring seal 62: Bellpil spring 66: Retaining ring (4 other people)

Claims (1)

[Scope of Claims] 1. A main body having a gate cavity and a communication hole extending through and opening into the cavity, and a recess or seat pocket around the opening of the communication hole leading to the gate cavity. a seat mechanism disposed within each recess; a sealing member associated with each seat mechanism for sealing a sealing surface of the body; and a sealing member positioned within the cavity between the seat mechanisms and passing through the communication hole. and a gate movable to open and close the flow path, and each of the sheet mechanisms includes an assembly that biases the sealing member with a disk spring to seal between the sheet and the main body sealing surface. A gate valve characterized by its curved shape. 2. The disc spring is held against the contour of the valve seat by a loading ring disposed around the seat ring and a retaining ring disposed in an annular groove molded into the wall of the recess. Claim 1 characterized in that:
Gate valve as described. 3. The gate valve of claim 1, wherein said disc spring is made of Inconel. 4. The gate valve according to claim 1, wherein the sealing member comprises an inner and outer sealing ring disposed in an inner and outer groove on an end surface of a seat ring disposed against the main body sealing surface. 5. The gate valve according to claim 4, wherein the sealing ring is a metal C-ring seal.